After years of paralysis, a man was able to pick up a cup of coffee and take a sip, thanks to experimental technology that allowed brain signals to control his arm with the help of a computer.
The researchers at Case Western Reserve University and University Hospitals Cleveland Medical Center documented their work in a new study published today in The Lancet medical journal. The study explains how a special electrical device, including implants in the brain and arm, allowed the man to control the movement of his right hand and arm years after being paralyzed from the shoulders down.
Dr. A Bolu Ajiboye, assistant professor of biomedical engineering at Case Western Reserve University and lead study author, explained their patient was the first to have such a high level of paralysis and yet still be able to move his arm via the device called BrainGate2.
"He literally cannot do anything on his own," said Ajiboye of the study subject, who was paralyzed eight years before he took part in the study. "With [this] system, he's been able to scratch his nose or be able to take a take a drink of a cup of coffee ... he now has the ability to do things."
To help the unnamed patient, doctors used the experimental neural interface system, BrainGate2, which is being studied in clinical trials at various institutions in the U.S. The system works by using electrical chips in the brain to transmit data to a computer, which then sends electrical signals to the muscles to move. In this case, two small chips were implanted in the man's brain in order to transmit data via a cable to a computer. The researchers also implanted small electrodes in his right arm, so that electrical impulses can cause the muscles to move.
In a person with full mobility, a desire to move the arm will result in an electrical signal down the spinal cord to the muscles that will result in the arms moving. The devices recreates that by having the implant "read" data from the patient's brain, which the computer translates into action that is then triggered by electrical signals to implants in the patient's arm.
"What we are doing in this project is circumventing the spinal injury by taking [the] pattern of brain activity to directly stimulate the muscles," Ajiboye explained.
Ajiboye said the patient was excited to take part in the study despite the invasive surgery in order to be able to do things for himself again.
"He said, 'You know what I really want to [do is] drink coffee,'" Ajiboye recalled. "We showed him drinking through a straw and drink coffee [via the device]."
He also has gotten to feed himself and even itch his nose with the device. However, since the device is experimental, the patient can only use it in the lab, but researchers hope to eventually have a device that he can use at home.
"He definitely keeps us wanting to innovate," said Ajiboye. "We want to give him more functionality."
Dr. Ben Walter, medical director of the Deep Brain Stimulation Program at University Hospitals Cleveland Medical Center and co-author of the study, said that this is still an early prototype with limitations. For example, the patient can't "feel" what he's holding; instead, he has to visually judge how much force to use in order to pick something up.
"In this particular application, he is not sensing the pressure and able to modulate the force based on feedback," Walter explained. "He can see what he's doing, but he can't feel."
While experimental, Walter said the implant is still an important move forward and could become much more streamlined in the future.
"In this case, he just thinks about moving and he moves," Walter said. "We're really putting things back together the way they're meant to be."